JP3751878B2 - Hydrophilic short fiber, nonwoven fabric containing the same, and method for producing the same - Google Patents

Description

【００７５】
【表２】

【００７６】
【表３】

【００７７】
実施例１〜６、実施例９、実施例１１においては、カード性が極めて良好であり、カードの衝撃によるセリシンの脱落も抑制することができ、十分な耐久親水性が得られた。実施例７、８は、カード性において若干劣るものの低速のカード機であれば実用レベルであった。実施例１０は、固着助剤としてキトサンを用いており、セリシンの固着性が若干劣っていたが、実用レベルであった。一方、比較例１は、セリシンの固着量が少なく、アニオン系親水性ウレタン樹脂の割合が大きいため、セリシンの親水特性が十分に得られず、耐久親水性に劣っていた。比較例２は、セリシンの固着量が多く、アニオン系親水性ウレタン樹脂の割合が少ないため、セリシンを繊維表面に固着することができず、脱落率が大きくなった。比較例３は、アニオン系親水性ウレタン樹脂の割合が少ないため、セリシンを繊維表面に固着することができず、脱落率が大きくなった。比較例４は、アニオン系親水性ウレタン樹脂の割合が大きいため、繊維間摩擦が大きくなり、カードでの開繊不良が生じネップが発生し、入り口のテーカーインロールへの巻き付きなどのトラブルが発生した。比較例５、６は、アニオン系親水性ウレタン樹脂を用いていないため、セリシンの固着性に劣り、脱落率が大きく、耐久親水性に劣っていた。比較例７は、アニオン系親水性ウレタン樹脂が繊維表面に選択的に付与されておらず、セリシンの固着具合にムラがあるため、セリシンの脱落率が大きく、セリシンがアニオン系親水性ウレタン樹脂に被覆されている可能性があり、耐久親水性に劣っていた。
【００７８】
【発明の効果】
以上説明したとおり、本発明によれば、トウの段階で繊維に対してセリシンを均一にかつ強固に固着し、開繊工程など外力が加わる不織布製造工程においてセリシンの脱落を伴うことなく、風合いのよい親水性短繊維、不織布及びその製造方法を提供できる。
【００７９】
また、本発明の不織布の少なくとも一部を構成する短繊維は、トウの段階でアニオン系親水性ウレタン樹脂とセリシンとアニオン系制電剤を段階的に所望の量を固着させることにより、セリシンの固着性に優れ、不織布製造時に容易に脱落することがないので、セリシンの対肌性、親水性などの機能を十分に発揮できるとともに、耐久親水性をより向上させることができる。特に、前記親水性ウレタン樹脂がオキシエチレン鎖を含有するウレタンプレポリマーに、重亜硫酸塩水溶液にて遊離イソシアネート基をブロック化したアニオン系親水性ウレタン樹脂であると、セリシンの固着性に優れる。
【００８０】
さらに、アニオン系制電剤を併用しているので、カード工程などにおける静電気などの発生を抑制し、ウェブの地合い形成および不織布製造工程性に優れるとともに、カードでの衝撃が少なくなるので、セリシンの脱落を抑制する効果も奏する。また、ポリビニルアルコールおよびキトサンから選ばれた少なくとも一種の固着助剤を併用することにより、セリシンの固着性が格段に向上する。
【００８１】
本発明の不織布は、前記親水性短繊維を２０mass％以上含有するカードウェブまたはエアレイウェブからなる、紙おむつ、生理用ナプキンの表面材などの衛生材料や化粧パフ、ウエットティッシュ、ワイピングクロスなどの日用雑貨などに好適な集合物である。特に、鞘成分を低融点樹脂とし、芯成分を低融点樹脂の融点より２０℃以上高い融点を有する高融点樹脂で構成された芯鞘型熱接着性複合短繊維を用いたカードウェブまたはエアレイウェブで構成され、鞘成分の低融点樹脂により構成する繊維同士を熱接着させることにより、嵩高、かつ柔軟であり、安価で、肌に優しい熱接着不織布を得ることができ、液透過性、ウェットバック性、ドライタッチ性、および繰り返し性に優れた紙おむつ、生理用ナプキンの表面材などの衛生材料に好適な不織布を得ることができる。[0001]
BACKGROUND OF THE INVENTION
  The present invention is suitable for sanitary materials such as disposable diapers and sanitary napkin surface materials, and daily goods such as cosmetic puffs, wet tissues, and wiping cloths. .
[0002]
[Prior art]
  Conventionally, the surface material of disposable diapers and sanitary napkins has been required to be liquid permeable to quickly transfer liquid from the human body to the absorbent, and after wetting with liquid, wet back prevents liquid backflow from the absorbent Sex is required. Furthermore, dry touch properties are required to give the skin a dry feeling, and repeatability is required. And the nonwoven fabric containing the polyolefin-type fiber which adhered the hydrophilic surfactant to the fiber surface conventionally is used.
[0003]
  In addition, various fibers and fiber aggregates in which sericin is applied to the fiber surface have been proposed as fibers that are gentle to human skin and are gentle to the skin. For example, as a method for simply attaching sericin, Japanese Patent No. 2998002 discloses a skin care fiber product in which a protein containing 20 to 40% serine as an essential component, preferably sericin is attached without adhering to the fiber surface. Has been proposed.
[0004]
  Japanese Patent Application Laid-Open No. 10-1872 discloses a method of attaching sericin to a fibrous material such as a nonwoven fabric. Japanese Patent Application Laid-Open No. 11-350352 discloses a short fiber cut by immersing a sericin aqueous solution in tow, drying and cutting. Japanese Patent Application Laid-Open No. 2001-271272 proposes a method for treating tow with a surfactant containing sericin and an alkali metal salt of an alkyl phosphate.
[0005]
  As a method of cross-linking sericin or insolubilizing by matrix treatment, JP-A-9-322911 discloses a non-woven fabric in which sericin is insolubilized by cross-linking treatment / matrix resin treatment to treat the fiber surface of the non-woven fabric. Proposed. As another proposal, JP-A-6-13772 discloses a method of fixing sericin in the recesses of the irregular cross-section synthetic fiber by crosslinking / water insolubilizing matrix resin treatment of sericin.
[0006]
  In addition, as a method of using sericin and a fixing agent in combination, JP-A-4-202855 uses a solution of a sericin aqueous solution and a fixing agent made of a synthetic resin of sericin insolubilizing drug, melamine, epoxy, or ester as a treatment liquid. Thus, a method for treating a synthetic fiber material is disclosed. Further, in JP-A-8-58006, after fixing sericin to a fiber fabric body and / or a nonwoven fabric body through a synthetic resin such as acrylic, urethane, polyester, epoxy, etc., the fiber fabric body and A fiber composite in which a nonwoven fabric body is bonded with a binder containing sericin is disclosed. In JP-A-10-195771, a synthetic fiber, a non-woven fabric, a woven fabric, a knitted fabric, etc., are crosslinked with a thermoplastic urethane containing a polyepoxy compound and / or a polyoxyethylene group and blocked with an isocyanate group, and a functional functionality. It has been proposed to perform a heat treatment with an aqueous solution containing a protein material. In JP-A-9-31847, it is proposed that a mixed aqueous solution of chitosan and sericin is attached to the fiber surface, and then dried and fixed by heat treatment to obtain a durable functional fiber product. Yes. Japanese Patent Application Laid-Open No. 2001-181976 proposes treating a fiber material or a fiber product with a treating agent containing chitosan and a polypeptide. Japanese Patent Laid-Open No. 2000-119966 proposes to impregnate a fiber base material coated with a synthetic resin into an aqueous solution composed of at least two of glycine, sericin and chitosan.
[0007]
[Problems to be solved by the invention]
  However, among the prior arts, in the case of fibers or fiber aggregates to which sericin is simply attached, the sericin is not sufficiently fixed to the fiber surface. Was easily removed, and the functions of the original sericin could not be fully exhibited. Further, in the method of using sericin and a fixing agent in combination, there is a problem that the texture becomes harder than the original fabric in the case of a fabric such as a woven or knitted fabric or a non-woven fabric. This is because, when an aqueous solution containing sericin or a fixing agent is applied or impregnated in the state of the fabric, the fixing agent enters not only between the fiber surfaces but also between the fibers, and bonds the fibers more than necessary. In addition, when the nonwoven fabric has a low density and a bulky material such as a heat-bonding nonwoven fabric, it is necessary to squeeze it with a squeeze roll or dry it with heat after applying the fixing agent. The bulk becomes lower than the initial bulk, and the texture becomes hard. Furthermore, since sericin and a fixing agent are mixed and applied, sericin is unnecessarily covered with the fixing agent, and the functions inherent to sericin cannot be fully exhibited.
[0008]
  In order to solve the above-described conventional problems, the present invention provides a hydrophilic short fiber in which sericin is firmly and firmly fixed to a fiber at the tow stage without causing sericin to drop off in the nonwoven fabric production process, and It aims at providing a good nonwoven fabric and its manufacturing method.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the hydrophilic short fiber of the present invention is at least in the state of tow which is a long fiber aggregate.AnionicHydrophilic urethane resin and sericinAnd anionic antistatic agentsAre applied to the fiber surface in the following proportions in this order, dried, and the tow is cut into short fibers.
(1)AnionicHydrophilic urethane resin: 15 to 300 parts by mass with respect to 100 parts by mass of sericin
(2) Sericin: 0.05 mass% or more and 3 mass% or less with respect to fiber mass
  Moreover, the nonwoven fabric of this invention contains the said short fiber 20mass% or more, and the remainder consists of a card web or an air web containing arbitrary short fibers.
(3) Anionic antistatic agent: 0.05 to fiber mass mass % Or more 0.6 mass %Less than
[0010]
  Further, the method for producing a nonwoven fabric of the present invention is at least in the state of tow which is a long fiber aggregate.AnionicHydrophilic urethane resin and sericinAnd anionic antistatic agentsWere applied to the fiber surface in the following order in the following ratio, dried, and the tow was cut into short fibers, and then formed into a card web or air lay web containing 20 mass% or more of the short fibers. It is characterized by.
(1) ToeAnionicContact treatment liquid containing hydrophilic urethane resin,AnionicThe process of providing a hydrophilic urethane resin so that it may become the range of 15 to 300 mass parts with respect to 100 mass parts of fixed amounts of sericin.
(2) Next, the process liquid which makes the processing liquid containing sericin contact, and is provided so that it may become the range of 0.05 mass% or more and 3 mass% or less with respect to fiber mass.
(3) Next, a treatment liquid containing an anionic antistatic agent is brought into contact with the fiber mass to 0.05 mass % Or more, 0.6 mass The process of providing so that it may become the range below%.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  In the present invention, the hydrophilic urethane resin is an anionic hydrophilic urethane resin.BecauseThe sericin can be prevented from falling off due to physical impact on the card, and the durability and hydrophilicity can be maintained.TheFurthermore, the anionic hydrophilic urethane resin is preferably an anionic hydrophilic urethane resin obtained by blocking a free isocyanate group of a urethane prepolymer containing an oxyethylene chain with bisulfite.
[0012]
  In the hydrophilic short fiber of the present invention, when at least one fixing aid selected from polyvinyl alcohol and chitosan is present on the fiber surface in a range of 30 to 300 parts by mass with respect to 100 parts by mass of sericin. The sericin fixing property is improved, and the sericin can be prevented from falling off in the nonwoven fabric manufacturing process such as the card process, and the durable hydrophilicity of the fiber or the nonwoven fabric can be improved.
[0013]
  In the hydrophilic short fiber of the present invention, an anionic antistatic agent is adhered to the fiber surface in a range of 0.05 mass% to 0.6 mass% with respect to the fiber mass.ByIn addition, it suppresses the generation of static electricity in the card process, etc., and is excellent not only in the formation of the web and the non-woven fabric manufacturing process, but also in the durable hydrophilicity of the fiber or the non-woven fabric, without irritation to the skin. . Furthermore, the anionic antistatic agent comprises at least one interface selected from alkyl phosphates having an alkyl group having 4 to 16 carbon atoms, alkyl ether phosphates, and aliphatic carboxylic acid soaps having 8 to 16 carbon atoms. An activator is preferred.
[0014]
  The hydrophilic short fiber of the present invention includes a core-sheath type thermoadhesive conjugate fiber composed of a high melting point resin having a sheath component having a low melting point resin and a core component having a melting point 20 ° C. higher than the melting point of the low melting point resin. Is preferable because it is bulky and a flexible heat-bonding nonwoven fabric can be obtained.
[0015]
  The nonwoven fabric of the present invention is as described above.AnionicSericin on hydrophilic urethane resin,Next, an anionic antistatic agentIt is preferable to contain 20 mass% or more of hydrophilic short fibers to which is fixed, and the remainder is made of a card web or an air web containing arbitrary short fibers. Furthermore, when the hydrophilic short fibers are used, a low melting point resin as a sheath component thermally bonds the constituent fibers to each other, thereby obtaining a bulky, flexible, inexpensive, and skin-friendly thermal bonding nonwoven fabric. It is possible to obtain a nonwoven fabric suitable for sanitary materials such as disposable diapers and sanitary napkin surface materials having excellent liquid permeability, wet-back properties, dry touch properties, and repeatability.
[0016]
  The nonwoven fabric of the present inventionThe anionic systemA treatment liquid containing a hydrophilic urethane resin is brought into contact, and the hydrophilic urethane resin is applied in a range of 15 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the fixed amount of sericin. The treatment liquid to be contained is brought into contact, and sericin is applied in a range of 0.05 mass% to 3 mass% with respect to the fiber mass,Subsequently, the treatment liquid containing the anionic antistatic agent is brought into contact with the fiber mass to 0.05 mass % Or more 0.6 mass % To give a range of less thanAnd drying, cutting the tow into short fibers, and then forming a card web or airlaid web containing 20 mass% or more of the short fibers to form a hydrophilic urethane resin film formed on the fiber surface. It is possible to obtain short fibers with sericin attached thereto efficiently, minimizing the loss of sericin due to external forces such as the opening process, and obtaining a nonwoven fabric containing sericin without impairing the original texture of the nonwoven fabric. Can do.In addition, it is preferable because it suppresses the generation of static electricity in the card process and the like, and is excellent in formation of the web and in the process of manufacturing the nonwoven fabric.
[0017]
  Further, when the treatment liquid containing sericin contains at least one fixing aid selected from polyvinyl alcohol and chitosan at a ratio of 30 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of sericin, the fiber surface When sericin is fixed on the hydrophilic urethane resin film formed on the surface, the adhesiveness to the urethane resin can be improved, which is preferable.
[0018]
  The fiber referred to in the present invention is a chemical fiber capable of forming a tow state which is an aggregate of long fibers. For example, regenerated fibers such as rayon and cupra, acrylic fibers, polyester fibers, polyamide fibers, polyolefins Synthetic fibers such as fibers, especially effective for fibers that are usually hydrophobic, and considering the processability of the nonwoven fabric, resins such as polyethylene, polypropylene, polymethylpentene, or copolymers thereof It is preferably a polyolefin-based fiber partially using. The cross-sectional shape of the fiber may be any of circular, irregular, hollow, etc., and may be any of a single form or a composite form such as a core-sheath type, an eccentric type, a parallel type, a split type, and a sea-island type. .
[0019]
  If used especially for heat-bonded nonwoven fabrics, the sheath component / core component is made of polyethylene / polypropylene, ethylene-propylene copolymer / polypropylene, polyethylene / polyester, etc., the sheath component is a low melting point resin, and the core component is a low melting point. A core-sheath type thermoadhesive conjugate fiber made of a high melting point resin having a melting point 20 ° C. higher than the melting point of the resin is preferable. If the difference in melting point is less than 20 ° C., the core component is also affected by heat at the time of heat processing, and the fiber itself may be bent to become a paper-like non-woven fabric, or the core component may be melted to form a film. There is. The melting point here means that measured by JIS-K-7122 (DSC method).
[0020]
  The fiber length constituting the nonwoven fabric of the present invention has a fiber length of 30 if it is a card process in order to sufficiently exhibit the effect of the present invention that is excellent in the processability of the fiber assembly such as a card process and an air array process. In the case of a short fiber consisting of ˜70 mm and an air laying process, a short fiber consisting of 5 to 40 mm is preferable.
[0021]
  The sericin used in the present invention is obtained by extracting sericin contained in silkworms and raw silk with water (non-hydrolyzed product), or extracted by partial hydrolysis with acid, alkali, electrolyzed water, enzyme, etc. Can be used. Moreover, what pulverized sericin by any one of following (1)-(3) can also be used from this extract.
(1) After adjusting a sericin extract to pH 3-5 with an organic acid or an inorganic acid, an organic flocculant or an inorganic flocculant is added to precipitate sericin, followed by filtration and drying to obtain a sericin powder.
(2) The sericin extract is mixed with a water-soluble organic solvent such as methanol, ethanol, dioxane, etc. to precipitate sericin, filtered and dried to obtain a sericin powder.
(3) As disclosed in JP-A-4-202435, a sericin extract is applied to an ultrafiltration membrane or a reverse osmosis membrane and then dried to obtain a sericin powder.
[0022]
  The molecular weight of sericin thus obtained is usually in the range of 500 to 500,000, any of which can be used, but preferably sericin having an average molecular weight of 7000 to 300,000. If the average molecular weight is less than 7000, it is excessively hydrolyzed, so that the effects of sericin described later may not be sufficiently exhibited. If the average molecular weight is larger than 300,000, it is difficult to dissolve in water and the workability may be impaired.
[0023]
  The amino acid composition of sericin, which is a natural protein, is similar to the natural moisturizing factor (NMF) involved in the adjustment of moisture in the skin stratum corneum, and particularly contains a lot of serine that is rich in hydrophilicity. Sericin containing a large amount of serine rich in hydrophilicity has an excellent moisturizing effect on the skin. Moreover, the effect which suppresses the active oxygen considered to be a cause of atopic dermatitis is also known. By applying this sericin to the fiber to reduce fiber irritation or to increase the hydrophilicity and moisture absorption / release properties of the fiber, it is intended to improve rough skin and atopic dermatitis.
[0024]
  The fixed amount of the sericin with respect to the fiber mass is in the range of 0.05 mass% to 3 mass%. The minimum of the fixed amount of preferable sericin is 0.1 mass% or more. The upper limit of the preferable amount of sericin is 1 mass% or less. When the fixed amount of sericin is less than 0.05 mass%, not only a sufficient hydrophilicity cannot be obtained, but also the effects of sericin such as moisture retention and active oxygen suppression are difficult to obtain. Moreover, even if the fixed amount of sericin exceeds 3 mass%, further hydrophilic performance cannot be obtained, which is uneconomical due to high cost.
[0025]
  As the sericin fixing agent,AnionicA hydrophilic urethane resin is used. Among the many sticking agentsAnionicSince the hydrophilic urethane resin has excellent adhesion to sericin and has hydrophilicity, the hydrophilicity and utility of sericin are not hindered.AnionicExamples of the hydrophilic urethane resin include those provided with a hydrophilic group such as a hydroxyl group, a carboxyl group, and a sulfone group.
[0026]
  The hydrophilic urethane resin used in the present invention isAn anionic hydrophilic urethane resin with an anionic hydrophilic groupBecauseIt is preferable in that it is the same as an anionic antistatic agent friendly to the human body to be described later, has good compatibility, strongly suppresses sericin detachment due to physical impact on the card, and maintains durable hydrophilicity.
[0027]
  Among the anionic hydrophilic urethane resins, it is possible to use an anionic hydrophilic urethane resin obtained by blocking a free isocyanate group of a urethane prepolymer containing an oxyethylene chain with bisulfite to fix sericin. Excellent in properties and preferable. Specifically, by using one or more compounds having a molecular weight of 200 to 20,000 having two or more active hydrogen atoms and an excess polyisocyanate, and if necessary, a chain extender having active hydrogen atoms, an isocyanate polymerization addition method is used. A low molecular weight urethane prepolymer containing free isocyanate groups is obtained. Next, an oxyethylene chain is added in the range of 10 to 40 mass% with respect to the low molecular weight urethane prepolymer. Thereby, the prepolymer which provided the hydrophilic property to the urethane substrate is obtained. Next, the free isocyanate group can be obtained by blocking the free isocyanate group with an aqueous bisulfite solution having a concentration of 3 times or less of the free isocyanate group and a concentration of 15 mass% or more. In the above, when the addition rate of the oxyethylene chain is less than 10 mass%, the hydrophilicity is low, and when it exceeds 40 mass%, the water resistance is lowered.
[0028]
  The hydrophilic urethane resin is fixed to the fiber in the range of 15 to 300 parts by mass with respect to 100 parts by mass of sericin. A more preferable lower limit of the fixing amount is 30 parts by mass or more with respect to 100 parts by mass of the sericin fixing amount. A more preferable upper limit of the fixing amount is 100 parts by mass or less with respect to 100 parts by mass of the sericin fixing amount. If the hydrophilic urethane resin is less than 15 parts by mass with respect to 100 parts by mass of sericin, sericin cannot be sufficiently adhered to the fiber surface and may fall off due to external force such as a fiber opening process. If the amount of adhering exceeds 300 parts by mass with respect to 100 parts by mass, the hydrophilic performance of sericin may be lost. In addition, the frictional resistance between the fibers increases, and there is a risk that the fiber group may be unsuccessfully opened in the fiber opening process, or fiber discharge from the card may be difficult.
[0029]
  While the said hydrophilic urethane resin satisfy | fills the said ratio, it is preferable that it adheres in 0.04 mass% or more and 3.4 mass% or less with respect to fiber mass. A more preferable lower limit of the fixing amount of the hydrophilic urethane resin is 0.1 mass% or more. A more preferable upper limit of the fixing amount of the hydrophilic urethane resin is 1 mass% or less. If the fixing amount of the hydrophilic urethane resin is less than 0.04 mass%, sericin cannot be sufficiently fixed to the fiber surface, and there is a risk of falling off due to an external force such as a card process. If it exceeds 3.4 mass%, Cost increases.
[0030]
  In the present invention, in addition to the hydrophilic urethane resin, other sticking agents may be used in combination, for example, an acrylic resin, an epoxy resin, etc., but from the compatibility with the sericin and the hydrophilic urethane resin, When at least one selected from polyvinyl alcohol and chitosan is fixed to the fiber as a fixing aid, the fixing property of sericin is further improved, and the sericin is prevented from falling off in the nonwoven fabric manufacturing process such as the card process, and the fiber or the nonwoven fabric. The durability and hydrophilicity of can be improved, and this is preferable. It is presumed that the fixing aid is formed into a high-dimensional film of sericin and improves durable hydrophilicity.
[0031]
  The fixing aid is preferably fixed to the fiber at a ratio of 30 to 300 parts by mass with respect to 100 parts by mass of sericin. A more preferable lower limit of the abundance of the fixing aid is 40 parts by mass or more. A more preferable upper limit of the abundance of the fixing aid is 200 parts by mass or less. If the amount of the fixing aid is less than 30 parts by mass, the hydrophilicity may be insufficient. When the amount of the fixing aid exceeds 300 parts by mass, not only the cost increases, but also the friction between fibers becomes large as in the case of the hydrophilic urethane resin, and the fiber group in the fiber opening process is poorly opened. There is a risk that it will be difficult to discharge the fiber from the card.
[0032]
  The hydrophilic short fibers of the present invention include the sericin and theAnionicBesides hydrophilic urethane resin,AnionicTo attach antistatic agentis necessary. In particular, it is preferable that the anionic antistatic agent is adhered in the range of 0.05 mass% or more and 0.6 mass% or less with respect to the fiber mass without causing irritation to the skin. The minimum of the adhesion amount of a more preferable anionic antistatic agent is 0.1 mass% or more. The upper limit of the adhesion amount of the more preferable anionic antistatic agent is 0.3 mass% or less. When the adhesion amount of the anionic antistatic agent is less than 0.05 mass%, static electricity is generated in the nonwoven fabric manufacturing process, particularly the card process, which may adversely affect web formation. If the adhesion amount of the electrostatic agent exceeds 0.6 mass%, not only the durability hydrophilic performance is lowered, but there is a possibility that troubles such as nep and winding around the cylinder due to poor opening of the card may occur.
[0033]
  Examples of the anionic antistatic agent include phosphoric acid surfactants such as alkyl phosphate esters and alkyl ether phosphate esters, soap surfactants such as aliphatic carboxylic acid soaps and amino acid soaps, and sulfonic acids such as alkane sulfonates. And surfactants such as alkyl sulfates and alkyl ether sulfates. Of these, in view of antistatic properties, card properties, and smoothness, phosphoric acid surfactants or soap surfactants are preferred, and alkyl phosphate esters and aliphatic carboxylic acid soaps are particularly preferred for smoothness, antibacterial properties. It is preferable because it has good electric and focusing properties, particularly good compatibility with sericin, and does not inhibit durable hydrophilicity. The alkyl phosphate ester is a sodium salt or potassium salt of an alkyl alcohol phosphate ester having an alkyl group having 4 to 16 carbon atoms. More preferably, the alkyl group has 8 or more and 12 or less carbon atoms. When the carbon number increases, the hydrophilicity tends to decrease and the antistatic effect tends to decrease. When the carbon number decreases, the affinity with fibers, particularly polyolefin fibers, tends to be weak, and the cost tends to increase. It is. In addition, the aliphatic carboxylic acid soap is preferably an aliphatic carboxylic acid soap having a fatty acid having 8 to 16 carbon atoms. More preferably, the fatty acid has 10 or more and 12 or less carbon atoms. When the carbon number increases, the hydrophilicity tends to decrease and the antistatic effect tends to decrease. When the carbon number decreases, the affinity with fibers, particularly polyolefin fibers, tends to decrease, and the cost tends to increase. The fatty acid is preferably a dibasic acid in terms of fiber convergence, smoothness, and antistatic properties.
[0034]
  Furthermore, in this invention, you may adhere components, such as a hydrophilicity improvement agent and a fiber-mechanical friction inhibitor, as needed. For example, polyoxyethylene or the like may be used as the hydrophilicity improver, and polyoxypropylene glycol, polyoxypropylene alkyl ether or the like may be used as the fiber-mechanical friction preventing agent. The hydrophilicity improver and the fiber-mechanical friction preventive agent are preferably attached in a range of 50 parts by mass or more and 450 parts by mass or less in total with respect to 100 parts by mass of sericin. When the total of the hydrophilicity improver and the fiber-mechanical friction preventive agent with respect to 100 parts by mass of sericin is less than 50 parts by mass, the hydrophilicity improving effect and the fiber-mechanical antifriction effect cannot be sufficiently obtained and exceed 450 parts by mass. And the cost tends to be higher.
[0035]
  Next, the manufacturing method of the hydrophilic short fiber of this invention is demonstrated. In the present invention,AnionicAfter applying a treatment liquid containing a hydrophilic urethane resin to the tow, a treatment liquid containing sericin is applied to the surface.Next, a treatment liquid containing an anionic antistatic agent is applied.Using the stepwise application method, sericin can be efficiently fixed on the hydrophilic urethane resin film formed on the fiber surface, and sericin can be minimized by external forces such as the opening process. it can.
[0036]
  Fixing aid, antistatic agent, hydrophilicity improver, fiber-mechanical friction improver, etc. added as necessaryAnionicYou may mix with the processing liquid containing a hydrophilic urethane resin or the processing liquid containing sericin, and you may provide to a fiber separately.
[0037]
  As a specific step-by-step method,AnionicA treatment liquid containing a hydrophilic urethane resin is brought into contact, and the hydrophilic urethane resin is applied in a range of 15 parts by mass to 300 parts by mass with respect to 100 parts by mass of the fixed amount of sericin. As the imparting method, at least one method selected from a contact method using a roll method, an impregnation method using a bath type oiling device, and a spraying method using a spray is adopted. At this time, the concentration of the treatment liquid may be adjusted to an amount to be added to the tow (water content of the tow) so that the desired hydrophilic urethane resin is fixed. As a method for adjusting the moisture content, for example, in the case of a roll-type contact method or an impregnation method, the amount of treatment liquid applied to the tow can be adjusted by a squeeze roll. When the spray method is used, the application amount can be adjusted by adjusting the spray amount. Also, when applying by impregnation method,AnionicA hydrophilic urethane resin can be uniformly applied to the fiber, which is preferable. Furthermore, if the impregnation method is used in the post process,AnionicAfter bringing the hydrophilic urethane resin-containing treatment liquid into contact, it is preferable that the water content of the tow is 20% or less to prevent the treatment liquid from being brought into the subsequent process.
[0038]
  Next, the treatment liquid containing sericin is brought into contact with the tow, and sericin is applied in a range of 0.05 mass% to 3 mass% with respect to the fiber mass. As the imparting method, at least one method selected from a contact method using a roll method, an impregnation method using a bath type oiling device, and a spraying method using a spray is adopted. When using sericin powder at this time, sericin may be dissolved in water at 20 to 60 ° C. or warm water alone and used as a treatment liquid. However, in order to promote dissolution, a surfactant is preferably mixed. . In addition, the concentration of the treatment liquid may be adjusted by adjusting the amount to be added to the tow (water content of the tow) so that the desired amount of sericin is fixed. For example, when an impregnation method is used, sericin can be uniformly applied to the fibers, and it is preferable, and when a spray method is used, it is economical and preferable.
[0039]
  In addition to the hydrophilic urethane resin, when other fixing aid is used in combination, it is mixed with a treatment liquid containing a hydrophilic urethane resin, a treatment liquid containing sericin, or a treatment liquid containing an antistatic agent described later. Alternatively, it may be applied before or after any of the treatments. Among them, it is preferable to use at least one fixing aid selected from polyvinyl alcohol and chitosan. Particularly, in the treatment liquid containing sericin, a range of 30 parts by mass to 300 parts by mass with respect to 100 parts by mass of sericin. It is preferable to contain.
[0040]
  In addition, the treatment liquid containing sericin has a hydrophilicity improver such as polyoxyethylene, polyoxypropylene glycol, polyoxypropylene alkyl ether, etc. It is preferable to contain a fiber-mechanical friction preventive agent. The hydrophilicity improver and the fiber-mechanical friction preventive agent are preferably contained in a total range of 50 parts by mass or more and 450 parts by mass or less with respect to 100 parts by mass of sericin.
[0041]
  ThenAnionicA treatment liquid containing an antistatic agent is brought into contact with the tow and applied so that the mass is 0.05 mass% or more and 0.6 mass% or less with respect to the fiber mass. As the application method, at least one method selected from a contact method using a roll method, an impregnation method using a bath type oiling device, and a spraying method using a spray is adopted. In consideration of the fixing property of the sericin, it is preferable to employ a spraying method by spraying. At this time, the concentration of the treatment liquid may be adjusted by adjusting the amount applied to the tow (water content of the tow) so that the desired amount of the antistatic agent is attached.
[0042]
  Next, the obtained tow is dried and cut into a desired fiber length to obtain a short fiber. The drying temperature is preferably in the range of 50 ° C to 130 ° C. A more preferable lower limit of the drying temperature is 60 ° C. or higher. A more preferable upper limit of the drying temperature is 120 ° C. or less. If the drying temperature is less than 50 ° C., the drying efficiency is poor and uneconomical. Further, depending on the resin constituting the fiber, there is a risk of causing shrinkage. If the drying temperature exceeds 130 ° C, sericin may be denatured.
[0043]
  Moreover, it is preferable that drying time is the range of 3 minutes or more and 30 minutes or less. A more preferable lower limit of the drying time is 5 minutes or more. A more preferable upper limit of the drying time is 20 minutes or less. If the drying time is less than 3 minutes, the tow may be partially undried. If the drying time exceeds 30 minutes, it is uneconomical and sericin may be denatured.
[0044]
  As an example of a specific method for producing the hydrophilic short fiber of the present invention, in a drawing process or a subsequent process in fiber production,AnionicWith hydrophilic urethane resin and sericinAnionic antistatic agentAndIn this orderA method of granting can be used. In particular, if polyolefin fibers are used, a polyolefin resin is spun by a known melt spinning machine to obtain a spun long fiber aggregate, and then subjected to a stretching treatment to obtain a stretched long fiber aggregate (tow). After the tow of tensionAnionicAt least one method selected from a contact method using a roll method, an impregnation method using a bath-type oiling device, and a spray method using a spray is used for the treatment liquid containing a hydrophilic urethane resin, and 0.04 mass% with respect to the fiber mass. It gives so that it may become 3.4 mass% or less above. ThenThe anionic systemAdopting at least one method selected from a contact method using a roll method, an impregnation method using a bath type oiling device, and a spraying method using a spray on a tow provided with a hydrophilic urethane resin, sericin Is added so as to be in the range of 0.05 mass% to 3 mass% with respect to the fiber mass. ThenAnionicTow with hydrophilic urethane resin and sericin,AnionicThe treatment liquid containing the antistatic agent is applied by a spraying method by spraying so that the mass is in the range of 0.05 mass% to 0.6 mass% with respect to the fiber mass. If necessary, the tow to which the desired treatment agent is applied is crimped by using a stuffer box type crimper or the like at any stage before or after each applying process after the stretching process. Then, excess moisture is dried by a hot air dryer having an atmospheric temperature of about 110 ° C., for example, and the applied treatment agents are fixed to the fiber surface. Next, the tow is cut into a desired fiber length to obtain hydrophilic polyolefin short fibers.
[0045]
  The nonwoven fabric of the present invention contains 20% by mass or more of the durable hydrophilic short fibers, and is produced based on a known nonwoven fabric forming method. For example, if it is formed on a card web and made into a thermal bond nonwoven fabric, sericin is fixed at the raw cotton stage, and sericin is less likely to fall off in the nonwoven fabric manufacturing process such as the card process, so sericin treatment after forming the fiber assembly The step of applying the liquid can be omitted, and the processing cost can be greatly reduced, which is preferable. The thermal bond nonwoven fabric is composed of a card web containing 20 mass% or more of a core-sheath type thermoadhesive composite staple fiber to which sericin is fixed, and a sheath is used by using a known heat treatment machine such as hot air or a hot roll. Original non-woven fabric that can be obtained by heat-bonding the fibers composed of the low melting point resin of the component, once the conventional thermal bond non-woven fabric is produced, and then fixed together using sericin in combination with a fixing agent The texture does not become harder than.
[0046]
  As another nonwoven fabric, an air-laying method in which short fibers are opened with air and accumulated on a net or the like to be manufactured into a nonwoven fabric can be employed.
[0047]
【Example】
  Hereinafter, an example is given and it demonstrates concretely. The card property, sericin drop-off rate, and durable hydrophilicity were measured as follows.
[0048]
  [Card characteristics]
  20 g / m at a speed of 20 m / min using a roller card under conditions of room temperature 25 ° C. and humidity 55%²Evaluation of the card property when the web was discharged was determined by the following items.
(1) Evaluation items
  A. Sink into the main cylinder
  B. Texture at the time of discharge (nep, vertical line, unevenness)
  C. Static electricity, cotton
(2) Criteria
  Y: None
  Δ: Slightly present
  ×: Available
[0049]
[Sericin dropout rate]
  Prepare 3 g of raw cotton before and after the carding test, put each in a conical flask with a stopper, add 100 ml of distilled water, soak in a 98 ° C hot water bath for 2 hours, and stir every 10 minutes. An extract was prepared. Next, after cooling the flask, the raw cotton and the extract were separated with a filter paper, and the amount of sericin fixed before and after passing through the card was measured by a protein quantification method by the Folin-Lowry method, and calculated by the following formula.
[0050]
  Drop-off rate (%) = [(fixed amount before test−fixed amount after test) × 100] / fixed amount before test
[0051]
[Durable hydrophilicity]
  In accordance with Japanese Patent Laid-Open No. 9-322911, the nonwoven fabric was cut into a size of 60 mm × 60 mm. Two filter papers are stacked on the nonwoven fabric to make a sample, and the sample is sandwiched between a pair of glassware for liquid flow (cylindrical with a height of 75 mm, an inner diameter of 36 mm, and a thickness of 3 mm) via a silicon packing. Fix it. Then, 40 ml of ion exchange water is injected into the upper glass apparatus for liquid passage, and the time T (sec) when the amount of the ion exchange water reached 20 ml is measured. Thereafter, the non-woven fabric is taken out and sandwiched between two filter papers, and a weight of 1 kg is placed on it and left for one minute. With this as one cycle, the number of cycles in which the above measurement was repeated until the time T of 20 ml passed reached 180 seconds was defined as the number of times of liquid passage.
[0052]
  [Example 1]
  (Preparation of sericin treatment solution)
  An aqueous solution containing 0.5 mass% of sericin, 0.4 mass% of polyvinyl alcohol as a fixing aid, polyoxyethylene as a hydrophilicity improver, and 0.7 mass% of polyoxypropylene glycol as a fiber-mechanical friction inhibitor Got ready.
[0053]
  (Preparation of hydrophilic urethane resin treatment liquid)
(1) Block copolymer polyether diol (OHV 46.7) having an average molecular weight of 2400 by adding ethylene oxide to polypropylene glycol (average molecular weight 1200): 21 parts by mass
(2) Adipic acid-1,6-hexanediol-neoventyl glycol type (molar ratio 10: 7: 4) Polyester diol (OHV 45.1): 56 parts by mass
(3) 1,6-hexanediol: 3 parts by mass
(4) Hexamethylene diisocyanate: 20 parts by mass
  The above four compounds were reacted in a nitrogen stream at 100 to 105 ° C. for 1 hour to obtain a urethane prepolymer. The urethane prepolymer had an NCO / OH ratio of 2.06, free NCO of 5.02%, and oxyethylene chain content in the prepolymer of 10.2%. The urethane prepolymer was cooled to 40 ° C., 20 parts by mass of dioxane and 65 parts by mass of a 25% aqueous sodium bisulfite solution at 40 ° C. were added and stirred. Subsequently, 202 parts by mass of water was added to obtain an anionic hydrophilic urethane resin (urethane resin A) as a white emulsion having a solid content of 30%. Next, the urethane resin A was diluted with water to prepare a treatment liquid having a urethane resin concentration of 0.5 mass%.
[0054]
  (Preparation of antistatic treatment solution)
  An aqueous solution containing 0.2 mass% of an alkyl phosphate potassium salt having 8 carbon atoms was prepared.
[0055]
  (Manufacture of fibers)
  An unstretched 6-tex core-sheath composite long fiber assembly (tow) having polyethylene terephthalate having a melting point of 245 ° C. as a core component and high-density polyethylene having a melting point of 132 ° C. as a sheath component is heated in warm water at 80 ° C. to 3.0%. After stretching twice, using a bath type oiling device, a treatment liquid with a bath temperature of 60 ° C. and an anionic hydrophilic urethane resin treatment liquid with a urethane resin concentration of 0.5 mass% is applied to the fiber, and a pair of fibers is formed at the outlet. The amount of treatment liquid applied to the tow was adjusted by squeezing with a squeeze roll, crimped with a crimper, and adjusted so that the water content of the tow was 20%.
[0056]
  Subsequently, using a spray type oiling device, the sericin treatment liquid was sprayed onto the fibers at a temperature of 25 ° C. to give a moisture content of 50%.
[0057]
  Next, using a spray type oiling device, the antistatic treatment liquid was sprayed onto the fibers at a temperature of 25 ° C. to give a moisture content of 50%.
[0058]
  Then, after drying heat treatment at 110 ° C. for 15 minutes, cutting was performed to obtain short fibers having a single fiber fineness of 2.2 dtex and a fiber length of 51 mm as shown in Table 1. The obtained short fibers are each subjected to a parallel card machine to form a fiber web, and are heat-treated at a temperature of 140 ° C. using a hot-air penetrating dryer, and have a basis weight of about 30 g / m.²A non-woven fabric was obtained.
[0059]
  [Example 2]
  Short fibers and nonwoven fabrics were obtained in the same manner as in Example 1 except that the sericin content in the sericin treatment liquid was 0.2 mass%.
[0060]
  [Example 3]
  Short fibers and nonwoven fabrics were obtained in the same manner as in Example 1 except that the sericin content in the sericin treatment liquid was 1 mass%.
[0061]
  [Example 4]
  AnionicShort fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that the urethane resin content in the hydrophilic urethane resin treatment liquid was 0.25 mass%.
[0062]
  [Example 5]
  AnionicShort fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that the urethane resin content in the hydrophilic urethane resin treatment liquid was 1 mass%.
[0063]
  [Examples 6 to 8]
  C in antistatic treatment liquid₈The same method as in Example 1 except that the content of alkyl phosphate ester potassium salt was 0.4 mass% (Example 6), 0.06 mass% (Example 7), and 2 mass% (Example 8), respectively. Short fibers and nonwoven fabric were obtained.
[0064]
  [Example 9]
  C as an antistatic agent in the antistatic treatment liquid₁₂Short fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that the alkyl phosphate ester potassium salt content was 0.2 mass%.
[0065]
  [Example 10]
  Short fibers and nonwoven fabrics were obtained in the same manner as in Example 1 except that chitosan was changed to 0.4 mass% as a fixing aid in the sericin treatment solution.
[0066]
  [Example 11]
  As hydrophilic urethane resin treatment liquid,
(1) Adipic acid-1,6 hexanediol-neopentyl glycol type (molar ratio 4: 3: 2) polyester diol (OHV 111.8 Av. 1.0): 43 parts by mass
(2) Polyether diol (OHV 110.5) randomly added to polyethylene glycol (average molecular weight 400) with ethylene oxide and propylene oxide-80: 20: 35 parts by mass
(3) Xylylene diisocyanate: 22 parts by mass
  The above three compounds were reacted at 95-100 ° C. for 1 hour in a nitrogen stream to obtain a urethane prepolymer. The urethane prepolymer had an NCO / OH ratio of 1.50, a free NCO of 3.16%, and an oxyethylene chain content in the prepolymer of about 30%. The urethane prepolymer was cooled to 50 ° C., and 40 parts of 30% aqueous potassium bisulfite solution was added and stirred. Next, 140 parts by mass of water was added to obtain a white emulsion anionic hydrophilic urethane resin (urethane resin B) having a solid content of about 40%. Next, short fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that the urethane resin B was diluted with water to obtain a treatment liquid having a urethane resin concentration of 0.5 mass%.
[0067]
  [Comparative Example 1]
  Short fibers and nonwoven fabrics were obtained in the same manner as in Example 1 except that the sericin content in the sericin treatment liquid was changed to 0.06 mass%.
[0068]
  [Comparative Example 2]
  Short fibers and nonwoven fabrics were obtained in the same manner as in Example 1 except that the sericin content in the sericin treatment liquid was changed to 7 mass%.
[0069]
  [Comparative Examples 3 to 4]
  AnionicA short fiber and a nonwoven fabric are obtained in the same manner as in Example 1 except that the urethane resin content in the hydrophilic urethane resin treatment liquid is 0.15 mass% (Comparative Example 3) and 17.5 mass% (Comparative Example 4). It was.
[0070]
  [Comparative Example 5]
  AnionicShort fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that an acrylic resin treatment liquid (manufactured by Takemoto Yushi Co., Ltd., DPF717, hereinafter referred to as acrylic resin A) was used instead of the hydrophilic urethane resin.
[0071]
  [Comparative Example 6]
  AnionicShort fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that an acrylic resin treatment liquid (manufactured by Takemoto Yushi Co., Ltd., DPF718, hereinafter referred to as acrylic resin B) was used instead of the hydrophilic urethane resin.
[0072]
  [Comparative Example 7]
  After the tow of Example 1 was stretched 3.0 times in warm water at 80 ° C., using a bath type oiling device, the bath temperature was 60 ° C., the anionic hydrophilic urethane resin concentration was 0.5 mass%, and sericin was 1. 25% by mass, 1% by mass of polyvinyl alcohol as a fixing aid, 1% by mass of polyoxyethylene as a hydrophilicity improver, and a treatment liquid containing 1.75% by mass of polyoxypropylene glycol as a fiber-mechanical friction preventive agent, Squeeze with a pair of squeeze rolls at the outlet to adjust the amount of treatment liquid applied to the tow, crimp with a crimper, adjust the tow moisture content to 20%, 110 ° C. for 15 minutes Short fibers and non-woven fabrics were obtained in the same manner as in Example 1 except that after the heat treatment for drying, the fibers were cut to obtain short fibers having a single fiber fineness of 2.2 dtex and a fiber length of 51 mm shown in Table 3.
[0073]
  The obtained results of Examples 1 to 11 are shown in Table 1 and Table 2, and the obtained results of Comparative Examples 1 to 7 are shown in Table 3.
[0074]
[Table 1]

[0075]
[Table 2]

[0076]
[Table 3]

[0077]
  In Examples 1 to 6, Example 9, and Example 11, the card properties were extremely good, the sericin could be prevented from falling off due to the impact of the card, and sufficient durable hydrophilicity was obtained. Examples 7 and 8 were at a practical level if they were low-speed card machines although they were slightly inferior in card properties. In Example 10, chitosan was used as a fixing assistant, and although the sericin fixing property was slightly inferior, it was at a practical level. On the other hand, Comparative Example 1 has a small amount of sericin,AnionicSince the ratio of the hydrophilic urethane resin was large, the hydrophilic property of sericin was not sufficiently obtained, and the durability hydrophilic property was inferior. Comparative Example 2 has a large amount of sericin fixed,AnionicSince the ratio of the hydrophilic urethane resin was small, sericin could not be fixed to the fiber surface, and the dropout rate increased. Comparative Example 3AnionicSince the ratio of the hydrophilic urethane resin was small, sericin could not be fixed to the fiber surface, and the dropout rate increased. Comparative Example 4AnionicSince the ratio of the hydrophilic urethane resin is large, the inter-fiber friction is increased, the card is not opened properly, nep is generated, and troubles such as winding of the entrance around the taker-in roll occur. Comparative Examples 5 and 6AnionicSince no hydrophilic urethane resin was used, the sericin was poor in adhesion, the drop-off rate was large, and the durability hydrophilicity was inferior. Comparative Example 7AnionicSince the hydrophilic urethane resin is not selectively applied to the fiber surface and the sericin is unevenly fixed, the sericin removal rate is large,AnionicThere was a possibility of being covered with a hydrophilic urethane resin, and the durability hydrophilicity was poor.
[0078]
【The invention's effect】
  As described above, according to the present invention, the sericin is uniformly and firmly fixed to the fiber at the tow stage, and the texture of the sericin does not fall off in the nonwoven fabric manufacturing process in which an external force such as a fiber opening process is applied. A good hydrophilic short fiber, a nonwoven fabric, and a method for producing the same can be provided.
[0079]
  Further, the short fibers constituting at least a part of the nonwoven fabric of the present invention are in the tow stage.AnionicWith hydrophilic urethane resin and sericinAnionic antistatic agentBy fixing the desired amount step by step, it has excellent sericin adhesion and does not easily fall off during the production of nonwoven fabrics, so it can fully demonstrate the functions of sericin against skin, hydrophilicity, and durability. The hydrophilicity can be further improved. In particular, when the hydrophilic urethane resin is an anionic hydrophilic urethane resin in which a free isocyanate group is blocked with an aqueous bisulfite solution on a urethane prepolymer containing an oxyethylene chain, sericin is excellent in adhesion.
[0080]
  In addition, an anionic antistatic agent is used in combinationBecauseIn addition, it suppresses the generation of static electricity in the card process and the like, and is excellent in web formation and non-woven fabric manufacturing process properties, and the impact on the card is reduced. Further, by using together with at least one fixing aid selected from polyvinyl alcohol and chitosan, the fixing property of sericin is remarkably improved.
[0081]
  The nonwoven fabric of the present invention is a hygienic material such as a disposable diaper, a sanitary napkin surface material, a cosmetic puff, a wet tissue, a wiping cloth, etc., which is made of a card web or air lay web containing 20% by mass or more of the hydrophilic short fibers. It is a suitable collection for household goods. In particular, a card web or air array using a core-sheath type heat-adhesive composite short fiber composed of a high-melting resin whose sheath component is a low-melting resin and whose core component is 20 ° C. higher than the melting point of the low-melting resin. By heat-bonding fibers composed of a web and composed of a low melting point resin as a sheath component, a bulky and flexible, inexpensive, skin-friendly heat-bonding nonwoven fabric can be obtained, liquid permeability, wet A nonwoven fabric suitable for sanitary materials such as disposable diapers and sanitary napkin surface materials having excellent backability, dry touch properties, and repeatability can be obtained.

Claims (9)

In the state of tow that is a long fiber aggregate, at least an anionic hydrophilic urethane resin, sericin, and an anionic antistatic agent are applied to the fiber surface in this order, dried, and the tow is cut at the following ratio: A hydrophilic short fiber composed of fixed short fibers.
(1) Anionic hydrophilic urethane resin: 15 to 300 parts by mass with respect to 100 parts by mass of sericin (2) Sericin: 0.05 to 3 mass% with respect to fiber mass
(3) Anionic antistatic agent: 0.05 mass % or more and 0.6 mass % or less with respect to the fiber mass The hydrophilic property according to claim 1 , wherein the anionic hydrophilic urethane resin is an anionic hydrophilic urethane resin obtained by blocking a free isocyanate group of a urethane prepolymer containing an oxyethylene chain with bisulfite. Short fiber. Further when sericin imparting, at least one fixing aid selected from polyvinyl alcohol and chitosan, any claim 1 to 2 is present in the range 300 parts by mass or less than 30 parts by weight per 100 parts by weight of sericin The hydrophilic short fiber according to crab. The anionic antistatic agent is selected from alkyl phosphate esters having an alkyl group having 4 to 16 carbon atoms, alkyl ether phosphate esters having 4 to 16 carbon atoms, and aliphatic carboxylic acid soaps having 8 to 16 carbon atoms. The hydrophilic short fiber according to any one of claims 1 to 3, which is at least one surfactant. The short fiber is a core-sheath type thermoadhesive conjugate fiber composed of a high melting point resin having a low melting point resin as a sheath component and a melting point higher than the melting point of the low melting point resin by 20 ° C or more . 5. The hydrophilic short fiber according to any one of 4 . A non-woven fabric comprising a card web or an air web containing 20 mass% or more of the short fibers according to any one of claims 1 to 5 and the rest containing any short fibers. The short fiber according to claim 5 is contained in an amount of 20 mass% or more, and the remainder is a card web or air lay web containing any short fiber, and the constituent fibers are thermally bonded to each other by a low melting point resin of the sheath component. Non-woven fabric. In the state of tow that is a long fiber aggregate, at least an anionic hydrophilic urethane resin, sericin, and an anionic antistatic agent are applied to the fiber surface in the following order in the following proportions, dried, and cut the tow A method for producing a non-woven fabric, characterized in that a short fiber is formed, and then formed into a card web or air lay web containing 20 mass% or more of the short fiber.
(1) contacting a treatment liquid containing an anionic hydrophilic urethane resin to the tow, the 15 parts by weight to 300 parts by weight or less of the range with respect to fixed amount 100 parts by weight of sericin and anionic hydrophilic urethane resin The process of giving.
(2) Next, the process liquid which makes the processing liquid containing sericin contact, and is provided so that it may become the range of 0.05 mass% or more and 3 mass% or less with respect to fiber mass.
(3) Next, the process which makes the processing liquid containing an anionic antistatic agent contact , and is provided so that it may become the range of 0.05 mass % or more and 0.6 mass % or less with respect to fiber mass . Treatment liquid containing the sericin, polyvinyl alcohol and at least one fixing aid selected from chitosan sericin 100 parts by weight with respect to 30 parts by mass or more, according to claim 8 containing in a proportion of less than 300 parts by weight Manufacturing method of non-woven fabric.